HSF 2 - Unit 2 Anatomy: Autonomic Innervation of the Thorax and Abdomen

Question 1

sensory is ______ information

Answer 1

afferent; goes from environment to CNS

Question 2

motor is ______ information

Answer 2

efferent; goes from CNS to muscle and glands

Question 3

somatic innervation concerns the …

Answer 3

body wall (skeletal muscle and skin)

Question 4

visceral innervation concerns the …

Answer 4

internal organs (heart)

Question 5

visceral motor autonomic innervation target tissues

Answer 5

smooth and cardiac muscle, glands; involuntary control

Question 6

how many neurons connect the CNS with the target tissue in visceral motor innervation?

Answer 6

2

Question 7

what are the types of visceral motor innervation?

Answer 7

sympathetic and parasympathetic

Question 8

what is sympathetic innervation associated with?

Answer 8

energy expenditure and increased metabolic rate: increased HR, strength of contraction and volume; dilation of coronary arteries to increase blood to heart, dilation of respiratory passages, constriction of pulmonary arteries, increased blood to skeletal muscles, decrease in blood to digestive organs, decrease in secretions by digestive glands, retention of urine and feces, increase in sweating, important for sexual function

Question 9

what is parasympathetic innervation associated with?

Answer 9

decreased HR, strength of contraction, and volume, constriction of coronary arteries to decrease blood flow to heart, constriction of respiratory passages, dilation of pulmonary arteries, decreased blood flow to skeletal muscles, increase in blood to digestive organs, increase in digestive gland secretion, elimination of urine and feces, important in sexual function

Question 10

what are the differences in anatomy of sympathetics and parasympathetics?

Answer 10

location of preganglionic cell bodies, relative lengths of preganglionic and postganglionic axons, size and location of ganglia

Question 11

location of preganglionic cell bodies

Answer 11

S: only in T1-L2 levels of the spinal cord (thoracolumbar distribution)
P: either in the brain or in the S2-S4 levels of the spinal cord (craniosacral distribution)

Question 12

relative lengths of the pre and postganglionic axons

Answer 12

S: about the same
P: pre is longer

Question 13

size of ganglia

Answer 13

S: larger
P: smaller and within the walls of the innervated organ

Question 14

what are the types of visceral sensation?

Answer 14

visceral pain and visceral afferents

Question 15

what is visceral pain? what can cause it?

Answer 15

dull, diffuse, or poorly localized pain caused by ischemia, prolonged muscle contraction (cramping) and distention (stretching)

Question 16

what are the visceral pain pathways of the thorax and the abdomen?

Answer 16

follow sympathetic pathways backwards as far as the spinal n. proper, then enter the dorsal root and cell bodies in dorsal root ganglia

Question 17

what are the visceral pain pathways of the pelvis?

Answer 17

follow parasympathetic pathways (pelvic splanchnic nn.) as far as the spinal n. proper, then pass through the dorsal root and cell bodies in the dorsal root ganglia

Question 18

what is the distribution of visceral afferents?

Answer 18

same as parasympathetics; carried in thorax and upper abdomen by vagus n., pelvic and lower abdomen carried by pelvic splanchnic nn.

Question 19

what are visceral afferents?

Answer 19

not perceived consciously but can reach consciousness at level of hunger and nausea

Question 20

what is referred pain?

Answer 20

when a stimulus affects an internal organ, usually causing visceral pain; at the same time, somatic pain can be felt in the same dermatome that belongs to the same spinal cord level, although there is no real stimulus to cause pain in the skin (eg: shoulder pain during a heart attack)

Question 21

sympathetic innervation of thoracic organs

Answer 21

cell body in the lateral horn-axon goes through ventral root-passes through white rami communicans and synapses with postganglionic neuron in paravertebral ganglion-postganglionic axon travels directly to thoracic organs for innervation . (thoracic splanchnic n.)

Question 22

sympathetic innervation of abdominal organs

Answer 22

cell body in the lateral horn-axon goes through ventral root-passes through white rami communicans and out to ganglion beneath the diaphragm to synapse with postganglionic neuron-postganglionic axon reaches to abdominal organ for innervation

Question 23

parasympathetic innervation of the thoracic and abdominal organs

Answer 23

vagus n. : cell body in the brain-axon travels to thoracic organ and synapses within organ with other neuron, same happens below diaphragm within abdominal organs

Question 24

parasympathetic innervation of the pelvis

Answer 24

(S2-S4) cell body in the lateral horn-axon goes through ventral root and spinal n. proper past the gray rami communicans (only this one in this section of the spinal cord)-goes out to synapse with postganglionic neuron within pelvic organ